JPS6210566A - Air conditioner - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an improvement in a control circuit for an air conditioner equipped with an injection compressor.

BACKGROUND ART In an air conditioner equipped with an injection compressor, an injection method is used in which a portion of the refrigerant in the expansion process is recovered into the compressor in order to improve the heating capacity at low outside temperatures.

A conventional example will be described below with reference to FIGS. 3 and 4.

FIG. 3 is a diagram of a refrigeration cycle equipped with a conventionally used gas injection circuit.

In the figure, reference numeral 1 denotes a compressor, and the refrigerant discharged by the compressor 1 enters an outdoor heat exchanger 3 via a four-way valve 2 and undergoes heat exchange with an outdoor heat exchanger 4. Next, the refrigerant flows into the gas-liquid separator 6 via the pressure reducing device 6, and the refrigerant that has entered in the gas-liquid two-phase state is separated into gas and liquid, and the liquid refrigerant is sent to the indoor fan 8 by the indoor heat exchanger 7. Heat is exchanged. The refrigerant that has entered the indoor heat exchanger 7 enters the suction port of the compressor 1 via the four-way valve 2, forming a refrigeration cycle. An injection circuit 9 injects the gas refrigerant separated by the gas-liquid separator 6 into the injection boat 11 of the compressor 1 by operating a solenoid valve 10.

Figure 4 shows a control circuit for an air conditioner that controls the refrigeration cycle described above. 12, 13.14 is the R phase of the three-phase power supply,
They are the S phase and the T phase, of which -a12 is provided with an operation switch 15, and between the two wires 12 and 13 are the crankcase for keeping the heat of the compressor 1, the low temperature side contact 19, and the high temperature side contact 2o. The first switch 21 is activated depending on the outside temperature.
series circuit is connected. Further, 22 is a room temperature thermostat for detecting the room temperature, and a parallel circuit of the compressor relay 17 and the outdoor motor 23 that drives the outdoor fan 4 is connected thereto. 24 is a switch for switching between cooling and heating, and a four-way valve 2
connected in series with 26 is an indoor motor that drives the indoor fan 8. Furthermore, the three-phase power supply 12, 13.14 is connected to the compressor 1
is connected.

The operation of the conventional example configured as described above will be described below.

First, during heating operation, the operation switch 16 and the cooling
By turning on the heating switching switch 24, the four-way valve 2 is excited and the indoor motor 26 is driven. During normal startup, the indoor temperature is low, so the room temperature thermostat 22 is turned on, the outdoor motor 23 is driven, and the compressor relay 17 is turned on.
is also excited.

By energizing the compressor relay 17, the normally open contact 26 of the compressor relay 17 is turned ON, and the compressor 1 is driven. Further, the normally closed contact 18 of the compressor relay 17 is turned off, so that the crankcase heater 16 is no longer energized. As a result of such control, the refrigerant flows as shown by the arrow in FIG. 3, and the air conditioner is operated for heating.

Next, when the outside temperature is low, for example below 6°C, the first switch 21 is set to the low temperature side (1 side in FIG. 4), and the solenoid valve 10
is excited. By energizing the electromagnetic valve 1o, the gas refrigerant separated by the gas-liquid separator 6 is injected into the injection port 11 of the compressor 1 via the injection circuit 9. Thereby, the amount of refrigerant discharged from the compressor 1 can be increased by the gas refrigerant further injected into the gas being compressed, and high performance heating operation can be performed.

Next, when the outside temperature is high, for example, 6°C or higher, the first switch 21 described above is switched to the high temperature side (2 side in Figure 4), and the magnetic valve 10 is demagnetized, injection is stopped, and normal capacity operation is resumed. . In this way, the injection circuit turns on and off depending on the outside temperature. Further, when the room temperature rises and the contact of the room temperature thermostat 22 is turned off, the outdoor motor 23 is stopped and the compressor relay 17 is demagnetized, its normally open contact 26 is turned off and the L compressor 1 is stopped.

When the compressor 1 stops, the pressure in the system is balanced between high pressure and low pressure, so the solenoid valve 10 receives the injection boat 11 as refrigerant pressure, albeit for a short time.
Since the temperature is higher on the side of the separator and lower on the side of the separator θ, a back pressure is applied to the valve seat (not shown) inside the solenoid valve 10, producing an abnormal "click, click" sound.

In order to prevent this abnormal noise, a first switch 21 is connected in parallel with the normally closed contact 18 of the compressor relay 17, and the compressor relay 17 is demagnetized, its normally open contact 26 is turned OFF, and the compressor 1 is stopped. At this time, the normally closed contact 18 excites the ONL solenoid valve 1o to forcibly open the solenoid valve 1o, thereby preventing the occurrence of abnormal noise.

Problems to be Solved by the Invention However, with the above configuration, the abnormal noise caused by the back pressure applied to the valve seat inside the solenoid valve 1° continues for several minutes until the refrigerant pressure in the system is balanced. figure,
The electromagnetic valve 10 has a state in which the compressor 1 is stopped, that is, the compressor relay 17 is demagnetized, and the normally closed contact 18 is ON.
Since it is constantly excited, it has the problem of wasting power.

In view of the above problems, the present invention aims to eliminate the abnormal noise caused by the back pressure applied to the solenoid valve installed in the injection circuit that occurs in the system when the room temperature thermostat is 0FFL and the compressor is stopped. In order to solve the above-mentioned problems, the air conditioner of the present invention has a simple electrical circuit configuration and eliminates wasted power consumed by the solenoid valve. A first switch that operates according to temperature and a second switch that operates based on temperature are connected in parallel to a normally closed contact of a compressor relay that controls the operation of the compressor.

Function The present invention has the above-described configuration, so that the compressor relay can be set to 0FF.
When the LFF stops, the normally closed contact of the compressor relay turns on, forcibly energizing the solenoid valve connected to it, preventing abnormal noise due to back pressure applied to this solenoid valve, and The solenoid valve is turned off after several minutes by a second switch that is activated depending on the temperature.

EXAMPLE An example of the present invention will be described below with reference to the drawings.

FIG. 1 shows a control circuit for an air conditioner according to an embodiment of the present invention.

1 is the compressor, 2 is the four-way valve, 12, 13.14 is the R phase, S phase and T phase of the three-phase power supply, 15 is the operation switch, 16 is the crankcase heater, 17 is the compressor relay, 18 is the compressor The normally closed contact of the relay 17, 19.20 the low temperature side contact and high temperature side contact of the first switch 21, 22 the room temperature thermostat, 23 the outdoor motor, 24 the cooling/heating switch, 26 the indoor motor, 26 the The normally open contact of the compressor relay 17 is the same as the structure shown in FIG. 4, and detailed explanation will be omitted.

Reference numeral 27 denotes a second switch that is activated by temperature, and is attached to the upper part of the compressor 1, as shown in the external view of the compressor in FIG. Further, the second switch 27 is the first switch 2 connected in series with the solenoid valve 10 that controls injection.
Crankcase heater 1 is connected in series to the high temperature contact of 1.
6 and the normally closed contact 18 of the compressor relay 17 are connected in parallel to the series circuit.

The operation of the air conditioner control circuit configured as above will be described below.

First, when heating operation starts, the room temperature is usually low and the room temperature thermometer 22
is turned on, and in this state, when the operation switch 16 and the cooling/heating switch 24 are turned on, the four-way valve 2 and the compressor relay 17 are excited, and the indoor motor 23 and the outdoor motor 26 are driven. When the compressor relay 17 is energized, the normally open contact 26 is turned on and the compressor 1 is driven.

At the same time, the normally closed contact 18 of the compressor relay 17 is turned OFF.
l. The crankcase heater 16 is no longer energized.

Next, when the outside temperature is low, for example below 6℃, the first
The switch 21 is set to the low temperature side (A side in Fig. 1), and the solenoid valve 1
o is excited. By energizing this electromagnetic valve 1o, the gas refrigerant separated by the gas-liquid separator 6 is injected into the injection port 11 of the compressor 1 via the injection injection circuit 9. When the outside temperature rises, the first switch 21 is set to the high temperature side (B side in FIG. 2), the solenoid valve 1o is demagnetized, and the injection is stopped. In this way, the first switch 21 is turned ON-OFF.
The injection circuit 9 is thereby controlled.

Further, when the outside temperature is high, for example, 6° C. or higher, and the first switch 21 is on the high temperature side (side B in FIG. 2), and the room temperature rises and the room temperature thermostat 22 is turned off, the outdoor motor 23 stops. Compressor relay 17 is demagnetized and its normally open contacts 2
6ba0FFLFF 1 also stops. As the compressor 1 was being driven, the upper part of the compressor 1 was heated, and the second switch 27 installed there received the heat and turned on when the temperature exceeded the set temperature (for example, 80 degrees Celsius). ing. When the compressor relay 17 is demagnetized, the normally closed contact 18 of the compressor relay 17 is ONL and the crankcase heater 16 is energized, and the solenoid valve 1o is energized via the second switch 27 and the first switch 21. Ru. In this way, the compressor 1 is driven, and the second switch 27 receives the heated heat.
If the compressor 1 stops when the compressor 1 is in the N state, the normally closed contact of the compressor relay turns ON, which excites the solenoid valve 1o, reducing the pressure in the system caused by the compressor 1 stopping. It is possible to eliminate abnormal noise from the valve seat (not shown) in the solenoid valve 10 due to the pressure applied to the solenoid valve 10 due to balance being opposite to the normal pressure. Next, the compressor 1 is stopped and its temperature gradually decreases due to the heat capacity of the compressor 1. After a few minutes, when the set temperature of the second switch reaches, for example, 40°C, the second switch 27 is turned OFF, and the solenoid valve 1° is turned off. Demagnetized.

In this embodiment, the behavior when the room temperature thermometer 22 is turned 0N-OFF is described, but when the operation switch 16 is turned 0N-OFF,
A similar effect can be obtained with FF.

Effects of the Invention As described above, the present invention is an injection circuit that is turned on and off using a solenoid valve, and a first switch that operates the solenoid valve is connected in series with a second switch that is operated depending on temperature to control the operation of the compressor. By connecting in parallel to the normally closed contact of the compressor relay, it is possible to prevent abnormal noise due to the back pressure applied to the solenoid valve caused by the pressure balance in the system when the compressor is stopped, and also to prevent the energization of the solenoid valve from occurring due to the temperature of the compressor. By controlling with the second switch that detects the power consumption, unnecessary power consumption can be eliminated.

[Brief explanation of drawings]

Fig. 1 is a control circuit diagram of an air conditioner showing an embodiment of the present invention, Fig. 2 is an external view of the compressor shown in Fig. 1, Fig. 3 is a general refrigeration cycle diagram, and Fig. 4 is a conventional It is a control circuit diagram of an air conditioner showing an example. 1... Compressor, 2... Four-way valve, 3...
... Outdoor heat exchanger, 5 ... Pressure reduction device, 7.
... Indoor heat exchanger, 9 ... Injection circuit, 10 ... Pressure reduction device, 17 ...
...Compressor relay, 18...--Normally closed contact of compressor relay, 21...First switch, 27...
...Second switch. Name of agent: Patent attorney Toshio Nakao and 1 other person!・
・-Pressure IMR 27---2nd switch 7chi Figure 3

Claims (1)

[Claims] A compressor for injection, a four-way valve, an outdoor heat exchanger, a pressure reducing device, and an indoor heat exchanger are connected in sequence, and an injection circuit having a solenoid valve is connected to the compressor, and a first circuit for operating the solenoid valve is connected in sequence. An air conditioner characterized in that a first switch and a second switch operated in series with temperature are connected in parallel to a normally closed contact of a compressor relay that controls the operation of the compressor.